Device and method of displaying images

ABSTRACT

This application relates to an image display device and method. In one aspect, the image display device includes a communication interface, a user interface, a memory and a processor. The processor may receive, from a first terminal through the communication interface, a stream including a plurality of images captured by the first terminal. The processor may also determine whether the received stream includes a first image in which no face is detected among the plurality of images. The processor may further, in response to determining that the received stream includes the first image, perform image processing on the first image to generate a second image. The processor may further display, through the user interface, the plurality of images by replacing the first image with the second image.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/729,520 filed on Oct. 10, 2017, which claims the benefit ofKorean Patent Application No. 10-2016-0130656, filed on Oct. 10, 2016,in the Korean Intellectual Property Office, the disclosures of both ofwhich are incorporated herein in their entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an image display device and an imagedisplay method, which are capable of preventing a user who makes a videocall with a counterpart from being exposed to inappropriate images.

2. Description of the Related Art

With the developments of communication technologies and theminiaturization of electronic devices, personal terminals have becomewidely spread to general customers. In particular, personal portableterminals, such as smart phones or smart tablets, have recently beenwidely used. Most terminals include a communication function. A user maysearch on the Internet using a terminal or may exchange messages withanother user.

Also, with the developments of small-sized camera technologies,small-sized microphone technologies, small-sized display technologies,and small-sized speaker technologies, most terminals such as smartphones include a camera, a microphone, a display, and a speaker. A usermay use the terminal to record a voice or capture a video including avoice. The user may confirm the recorded voice through the speakerincluded in the terminal or the captured video through the displayincluded in the terminal.

Also, the user may share the recorded voice or the captured video withanother user using the communication function of the terminal. The usermay send a previously recorded voice or a previously captured video toanother user. Also, the user may send a voice or a video, which is beingcurrently recorded or captured by the terminal, to another user in realtime.

Also, at the same time, another user may send a voice or a video, whichis being currently recorded or captured by his or her own terminal, tothe user in real time. The display included in the terminal of the usermay simultaneously display the video that is being currently captured bythe terminal of the user and the video that is being currently capturedby the terminal of another user. Also, the speaker included in theterminal of the user may simultaneously reproduce the voice that isbeing currently recorded by the terminal of another user. In otherwords, the user and another user may make a video call to each otherusing their own terminals.

The user and another user may or may not be acquainted with each other.A plurality of terminals, including the terminal of the user and theterminal of another user, may be connected to a server. The server maymediate between the terminal of the user and the terminal of anotheruser. Therefore, even though the user and another user are notacquainted with each other, the user and another user may make a videocall to each other through the mediation of the server.

When the user makes a video call with the counterpart, the user may beexposed to obscene images from the counterpart. In particular, when theuser makes a video call with an unacquainted counterpart, it is highlylikely that the user will be exposed to obscene images from thecounterpart.

For example, a terminal of the user may receive a naked body image ofthe counterpart, which is captured by a terminal of the counterpart,through a video call session. The terminal of the user displays thereceived image and thus the user may be exposed to the obscene image. Ifthe user is exposed to the obscene image that the user does not want,the user may feel sexual shame or discomfort.

SUMMARY

Some example embodiments may provide an image display apparatus and animage display method, which are capable of preventing a user who makes avideo call with a counterpart from being exposed to obscene images fromthe counterpart.

Some example embodiments may provide an image display device and animage display method, which are capable of preventing a user who makes avideo call with a counterpart from sexual shame or discomfort that theuser may feel from images from the counterpart.

Some example embodiments may provide an image display device and animage display method, which are capable of guiding a proper video callbetween users.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

An image display method according to an embodiment includes: receiving,from a first terminal, a stream including a plurality of images capturedby the first terminal; determining whether there is an image in which noface is detected among the plurality of images included in the stream;when it is determined that there is the image in which no face isdetected, performing image processing on the image in which no face isdetected among the plurality of images; and displaying the plurality ofimages by replacing the image in which no face is detected with theimage on which the image processing has been performed.

According to another embodiment, provided is a computer-readablerecording medium having recorded thereon a program to execute the imagedisplay method in a computer.

An image display device according to another embodiment includes: acommunication interface; a user interface; a memory storinginstructions; and a processor, wherein the processor is configured toexecute the instructions to: receive, from a first terminal through thecommunication interface, a stream including a plurality of imagescaptured by the first terminal; determine whether there is an image inwhich no face is detected among the plurality of images included in thestream; when it is determined that there is the image in which no faceis detected, perform image processing on the image in which no face isdetected among the plurality of images; and display, through the userinterface, the plurality of images by replacing the image in which noface is detected with an image on which the image processing has beenperformed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings.

FIG. 1 is a network configuration diagram illustrating an environment inwhich an image display device according to an embodiment operates.

FIG. 2 is a block diagram of an image display device according to anembodiment.

FIG. 3 is a flowchart of an image display method according to anembodiment.

FIG. 4 illustrates a sample image selected among a plurality of imagesincluded in a stream, according to an embodiment.

FIG. 5 illustrates another sample image selected among a plurality ofimages included in a stream, according to an embodiment.

FIG. 6 is a flowchart of a process of processing an image, according toan embodiment.

FIG. 7 is a flowchart of a process of attempting to detect a face to aprocess of selecting a target image, according to an embodiment.

FIG. 8 is a reference diagram for describing a process of selecting asample image, according to an embodiment.

FIG. 9 is a flowchart of a process of attempting to detect a face to aprocess of selecting a target image, according to another embodiment.

FIG. 10 is a flowchart of a process of attempting to detect a face to aprocess of selecting a target image, according to another embodiment.

FIG. 11 is a reference diagram for describing a process of selecting asample image, according to another embodiment.

FIG. 12 is a flowchart of a process of attempting to detect a face to aprocess of selecting a target image, according to another embodiment.

FIG. 13 is a reference diagram illustrating a selected target regionaccording to an embodiment.

FIG. 14 is a reference diagram illustrating a selected target regionaccording to another embodiment.

FIG. 15 is a reference diagram illustrating a selected target regionaccording to another embodiment.

FIG. 16 illustrates an image, on which image processing has beenperformed, according to an embodiment.

FIG. 17 illustrates an image, on which image processing has beenperformed, according to another embodiment.

FIG. 18 illustrates an image, on which image processing has beenperformed, according to another embodiment.

FIG. 19 illustrates an image, on which image processing has beenperformed, according to another embodiment.

FIG. 20 is a flowchart of an image display method according to anotherembodiment.

FIG. 21 is a flowchart of an image display method according to anotherembodiment.

FIG. 22 is a diagram for explaining a state in which a second terminaldisplays a received image when a first terminal transmits a streamincluding an image in which no face is detected to a second terminal.

DETAILED DESCRIPTION

Advantages and features and a method of achieving the same will be moreclearly understood from embodiments described below in detail withreference to the accompanying drawings. However, the present disclosureis not limited to the following embodiments and may be implemented invarious different forms. The embodiments are provided merely to completedisclosure and to provide those of ordinary skill in the art with thecategory of the present disclosure. The present disclosure is definedonly by the claims. Wherever possible, the same reference numbers willbe used throughout the specification to refer to the same or likecomponents.

Also, it will be understood that although the terms “first”, “second”,etc. may be used herein to describe various components, these componentsshould not be limited by these terms. These terms are only used todistinguish one component from another. Therefore, a first componentused herein may be a second component within the technical scope of thepresent disclosure.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the present disclosure. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated components and/or steps, but do not preclude thepresence or addition of one or more other components and/or steps.

Unless otherwise defined, all terms used herein have the same meaning ascommonly understood by those of ordinary skill in the art. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure and will not be interpreted in an idealized or overlyformal sense unless expressly so defined herein.

Hereinafter, terminals 100 and 150 and methods of controlling the same,according to embodiments, will be described in detail with reference toFIGS. 1 to 13 .

Hereinafter, image display devices 100 and 150 and image displaymethods, according to embodiments, will be described in detail withreference to FIGS. 1 to 20 .

FIG. 1 is a network configuration diagram illustrating an environment inwhich image display devices 100 and 150 according to an embodimentoperate. Referring to FIG. 1 , the environment in which the imagedisplay devices 100 and 150 operate may include a first image displaydevice 100, and a second image display device 150 connected to the firstimage display device 100.

According to another embodiment, the environment in which the imagedisplay devices 100 and 150 operate may further include a server 200connected to the first image display device 100 or the second imagedisplay device 150. The environment in which the image display devices100 and 150 operate may not include the server 200.

The first image display device 100 may be a terminal. For convenience ofdescription, the first image display device 100 and the first terminal100 are interchangeably used herein.

The first terminal 100 may be, for example, a desktop computer, a laptopcomputer, a smart phone, a smart tablet, a smart watch, a mobileterminal, a digital camera, a wearable device, or a portable electronicdevice. The first terminal 100 may execute programs or applications.

The first terminal 100 may be connected to a communication network. Thefirst terminal 100 may be connected to an external device via thecommunication network. The first terminal 100 may transmit data to theconnected external device or receive data from the connected externaldevice.

The communication network connected to the first terminal 100 mayinclude a wired communication network, a wireless communication network,or a composite communication network. The communication network mayinclude a mobile communication network such as 3 G, Long Term Evolution(LTE), or LTE-A. The communication network may include a wired orwireless communication network such as Wi-Fi, Universal Mobile TelephoneSystem/General Packet Radio Service (UMTS/GPRS), or Ethernet. Thecommunication network may include a short-range communication networksuch as Magnetic Secure Transmission (MST), Radio FrequencyIDentification (RFID), Near Field Communication (NFC), ZigBee, Z-Wave,Bluetooth, Bluetooth Low Energy (BLE), or InfraRed (IR) communication.The communication network may include Local Area Network (LAN),Metropolitan Area Network (MAN), or Wide Area Network (WAN).

FIG. 2 is a block diagram illustrating the configurations of the imagedisplay devices 100 and 150 according to an embodiment. Referring toFIG. 2 , each of the image display devices 100 and 150 according to anembodiment may include an input interface 101, a controller 102, astorage 103, a communication interface 104, and an output interface 105.

The input interface 101 may receive an external signal. The inputinterface 101 may receive signals from users of the image displaydevices 100 and 150. Also, the input interface 101 may receive a signalfrom an external device. The input interface 101 may include, forexample, a microphone, a camera, a keyboard, a mouse, a track ball, atouch screen, a button, a switch, a sensor, a network interface, orother input devices.

The input interface 101 may receive light from the exterior through thecamera included in the input interface 101. The input interface 101 mayreceive light emitted from an external object or light reflected from anexternal object. The input interface 101 may capture images of the usersof the image display devices 100 and 150 through the camera.

The input interface 101 may receive a voice from the exterior throughthe microphone included in the input interface 101. The input interface101 may receive voices from the users of the image display devices 100and 150. Also, the input interface 101 may receive voices from anexternal voice reproduction device. The input interface 101 may recordvoices of the users of the image display devices 100 and 150 through themicrophone.

The controller 102 may control operations of the image display devices100 and 150. The controller 102 may be connected to the componentsincluded in the image display devices 100 and 150. The controller 102may control operations of the components included in the image displaydevices 100 and 150.

The controller 102 may process a signal. The controller 102 may processa signal received by the input interface 101. For example, thecontroller 102 may process a user's request received through the inputinterface 101. The controller 102 may process an image of a usercaptured by the camera included in the input interface 101. Thecontroller 102 may process a user's voice recorded by the microphoneincluded in the input interface 101.

The controller 102 may process a signal received by the communicationinterface 104. For example, the controller 102 may process a user'srequest received through the communication interface 104. The controller102 may process an image or voice of another user received through thecommunication interface 104.

The controller 102 may control the operations of the image displaydevices 100 and 150 in response to a signal received by the inputinterface 101. The controller 102 may control the operations of theimage display devices 100 and 150 in response to a user's requestreceived through the input interface 101.

The controller 102 may perform an arithmetic operation. The controller102 may perform an arithmetic operation according to a signal receivedby the input interface 101. The controller 102 may perform an arithmeticoperation using a signal received by the input interface 101 or datastored in the storage 103. For example, the controller 102 may encode animage captured by the camera included in the input interface 101. Thecontroller 102 may encode a voice recorded by the microphone included inthe input interface 101.

The controller 102 may decode an image or voice of another user receivedthrough the communication interface 104. The controller 130 may performpostprocessing on the decoded image or voice. For example, thecontroller 102 may perform image processing on an image of another userreceived through the communication interface 104.

The controller 102 may perform control such that the result of thearithmetic operation is stored in the storage 103. The controller 102may perform control such that the result of the arithmetic operation isoutput by the output interface 105.

The controller 102 may include, for example, a central processing unit(CPU), a graphic processing unit (GPU), a micro controller unit (MCU),or a microprocessor.

The storage 103 may store data. The storage 103 may store data to beused when the controller 102 performs the arithmetic operation. Thestorage 103 may store the result of the arithmetic operation performedby the controller 102. For example, the storage 103 may store an imageor a voice encoded by the controller 102. The storage 103 may store datato be transmitted to the exterior through the communication interface104, or may store data received from the exterior through thecommunication interface 104.

The storage 103 may include a volatile memory or a non-volatile memory.The storage 103 may include, for example, flash memory, read-only memory(ROM), random access memory (RAM), electrically erasable read-onlymemory (EEROM), erasable programmable read-only memory (EPROM),electrically erasable and programmable read-only memory (EEPROM), harddisk drive (HDD), register, or the like. The storage 103 may include,for example, a file system, a database, or an embedded database.

The communication interface 104 may transmit data to the exterior orreceive data from the exterior. The communication interface 104 maytransmit data to another image display terminal 100 or 150 or the server200. The communication interface 104 may transmit data to another imagedisplay device 100 or 150 or the server 200. The communication interface104 may transmit the result of the arithmetic operation performed by thecontroller 102 to the exterior. Also, the communication interface 104may transmit data stored in the storage 103 to the exterior. Thecommunication interface 104 may receive external data to be used whenthe controller 102 performs the arithmetic operation.

Data to be transmitted by the communication interface 104 or datareceived by the communication interface 104 may be stored in the storage103. For example, the communication interface 104 may transmit anencoded image or voice stored in the storage 103 to the server 200 oranother image display device 100 or 150. Also, the communicationinterface 104 may receive an image or a voice encoded by anotherterminal 100 or 150 from another terminal 100 or 150.

The communication interface 104 may include a long-range networkinterface such as a 3G module, an LTE module, an LTE-A module, a Wi-Fimodule, a WiGig module, an Ultra Wide Band (UWB) module, or a LAN card.Also, the communication interface 104 may include a short-range networkinterface such as an MST module, a Bluetooth module, an NFC module, anRFID module, a ZigBee module, a Z-Wave module, or an IR module. Inaddition, the communication interface 104 may include other networkinterfaces.

The output interface 105 may output a signal to the exterior. The outputinterface 105 may, for example, display a screen, reproduce a sound, oroutput a vibration. The output interface 105 may include a display, aspeaker, a vibrator, an oscillator, or other output devices.

The output interface 105 may display a screen. The controller 102 maycontrol the output interface 105 to display a screen. The outputinterface 105 may display a user interface. The output interface 105 maydisplay another screen in response to a user input.

The output interface 105 may display data. The output interface 105 maydisplay the result of the arithmetic operation performed by thecontroller 102. The output interface 105 may display data stored in thestorage 103. The output interface 105 may display data received by thecommunication interface 104.

The output interface 105 may include a flat-panel display device such asa liquid crystal display (LCD), an organic light-emitting diode (OLED),or a plasma display panel (PDP). The output interface 105 may include acurved display or a flexible display. The output interface 105 mayinclude a touch screen.

The output interface 105 may display the image of the user captured bythe first image display device 100 or the image of another user capturedby the second image display device 150. Also, the output interface 105may reproduce the voice of the user recorded by the first image displaydevice 100 or the voice of another user captured by the second imagedisplay device 150.

The second image display device 150 may be a terminal. For convenienceof description, the second image display device 150 and the secondterminal 150 are interchangeably used herein.

A type of the second terminal 150 may be identical to or different froma type of the first terminal 100. The second terminal 150 may executeprograms or applications.

The second terminal 150 may be connected to a communication network. Thesecond terminal 150 may be connected to an external device via thecommunication network. The second terminal 150 may transmit data to theconnected external device or receive data from the connected externaldevice.

The second terminal 150 may be connected to the first terminal 100. Thesecond terminal 150 may be connected to the first terminal 100 via thecommunication network. The second terminal 150 may transmit data to thefirst terminal 100 or receive data from the first terminal 100.

The first terminal 100 and the second terminal 150, which are connectedto each other, may exchange messages, files, voice data, images, orvideos with each other. The second terminal 150 may establish a voicecall session or a video call session with the first terminal 100. Thevideo call session may be established using, for example, TransmissionControl Protocol (TCR), User Datagram Protocol (UDP), or Web Real-TimeCommunication (WebRTC). The user of the first terminal 100 and the userof the second terminal 150 may make a voice call or a video call witheach other.

The video call session may be directly established between the firstterminal 100 and the second terminal 150. According to anotherembodiment, the video call session may be established between the firstterminal 100 and the second terminal 150 via at least one device. Forexample, the video call session may include a session establishedbetween the first terminal 100 and the server 200 and a sessionestablished between the server 200 and the second terminal 150.

The first terminal 100 and the second terminal 150 may directly exchangedata with each other. Also, the first terminal 100 and the secondterminal 150 may exchange data with each other via the server 200 oranother mediating device.

The server 200 may be connected to the first terminal 100 or the secondterminal 150. When the server 200 is connected to the first terminal100, the server 200 may exchange data with the first terminal 100 viathe communication network. When the server 200 is connected to thesecond terminal 150, the server 200 may exchange data with the secondterminal 150 via the communication network.

The server 200 may receive data from the first terminals 100. The server200 may perform an arithmetic operation using the data received from thefirst terminal 100. The server 200 may transmit the result of thearithmetic operation to the first terminal 100 or the second terminal150. The server 200 may receive data from the second terminals 150. Theserver 200 may perform an arithmetic operation using the data receivedfrom the second terminal 150. The server 200 may transmit the result ofthe arithmetic operation to the first terminal 100 or the secondterminal 150.

Hereinafter, specific operations of the image display devices 100 and150, which perform image display methods, according to an embodimentwill be described in detail with reference to FIGS. 3 to 20 .

FIG. 3 is a flowchart of an image display method according to anembodiment. Referring to FIG. 3 , in operation S100, a stream includinga plurality of images captured by the first terminal 100 may be receivedfrom the first terminal 100.

The communication interface 104 of the second terminal 150 may establisha video call session with the first terminal 100. The communicationinterface 104 of the second terminal 150 may receive the stream from thefirst terminal 100 through the video call session. The stream mayinclude a plurality of images. For example, the stream may include avideo or at least two still images.

The plurality of images included in the stream may be images captured bythe camera included in the input interface 101 of the first terminal100. The second terminal 150 may continuously receive a plurality ofimages, which are being continuously captured by the first terminal 100,through the stream.

The plurality of images may be images of the user of the first terminal100. For example, the plurality of images may include an image of a faceof the user of the first terminal 100. The plurality of images may be animage of a body of the user of the first terminal 100.

The second terminal 150 may directly receive the stream from the firstterminal 100. According to another embodiment, the second terminal 150may receive the stream from the first terminal 100 via the server 200.

In operation S110, face detection may be attempted in each of one ormore sample images selected among the plurality of images included inthe stream. The controller 102 of the second terminal 150 may select oneor more sample images among the plurality of images included in thestream. The controller 102 of the second terminal 150 may select asample image among the plurality of images randomly or according to aspecific rule.

For example, the controller 102 of the second terminal 150 may select anew sample image among newly received images in the stream at eachspecific period. The controller 102 of the second terminal 150 mayselect a new sample image among the entire images received later thanthe most recently selected sample image in the stream. The controller102 of the second terminal 150 may select the new sample image randomlyor according to a specific rule.

The controller 102 of the second terminal 150 may attempt to detect theface in each of the selected one or more sample images. The controller102 of the second terminal 150 may detect whether a portioncorresponding to a face of a person exists in one image using an opensource library such as Open Source Computer Vision (OpenCV) or othercommercial programs. The controller 102 of the second terminal 150 maydetect whether the portion corresponding to the face exists with respectto each sample image.

FIG. 4 illustrates a sample image selected among the plurality of imagesincluded in the stream, according to an embodiment. Also, FIG. 5illustrates another sample image selected among the plurality of imagesincluded in the stream, according to an embodiment. The controller 102of the second terminal 150 may attempt to detect a face in each of thesample image of FIG. 4 and the sample image of FIG. 5 .

Referring to FIG. 3 again, in operation S120, it may be determined thatthe face has not been detected in at least some of the sample images.The controller 102 of the second terminal 150 may determine whether aportion corresponding to a face exists with respect to each sampleimage. As the determination result, the controller 102 of the secondterminal 150 may determine that the face has not been detected in atleast one of the sample images.

For example, the controller 102 of the second terminal 150 may determinethat the face has been detected in a sample image corresponding to anupper body of the user of the first terminal 100, like in the image ofFIG. 4 . On the other hand, the controller 102 of the second terminal150 may determine that the face has not been detected in a sample imagecorresponding to a lower body of the user of the first terminal 100,like in the image of FIG. 5 .

Referring to FIG. 3 again, in operation S130, image processing may beperformed on at least one of the plurality of images included in thestream. When it is determined that the face has not been detected in atleast some of the sample images, it may be determined that the pluralityof images received from the first terminal 100 include obscene images.For example, when an image such as the image of FIG. 5 is included inthe plurality of images received from the first terminal 100, it may bedetermined that the plurality of images include obscene images.

The controller 102 of the second terminal 150 may perform imageprocessing on at least one of the plurality of images so as to preventthe user of the second terminal 150 from being exposed to the obsceneimages. The controller 102 of the second terminal 150 may perform imageprocessing on all the plurality of images or some images selected amongthe plurality of images.

FIG. 6 is a flowchart of operation S130 of performing the imageprocessing, according to an embodiment. Referring to FIG. 6 , inoperation S131, one or more target images may be selected among theplurality of images included in the stream.

The controller 102 of the second terminal 150 may select one or moretarget images, on which image processing is to be performed, among theplurality of images. For example, the controller 102 of the secondterminal 150 may select all the plurality of images included in thestream as the target images.

According to another embodiment, the controller 102 of the secondterminal 150 may perform image processing on one or more imagescorresponding to the sample image, in which it is determined that theface has not been detected, among the plurality of images. The imagescorresponding to the sample image may be the entire images receivedwithin a specific time range from the time at which the sample image hasbeen received among the plurality of images.

For example, it is assumed that twenty images per second arecontinuously received through the stream. Also, it is assumed that themost recently received image is selected as a new sample image whenevera period of 4 seconds is returned. Also, it is assumed that it has beendetermined that the face has not been detected in two sample images. Thetime when the two sample images have been received may be a time pointof 24 seconds and a time point of 32 seconds. The images correspondingto the two sample images may be about eighty images received within atime range from a time point of 22 seconds to a time point of 26 secondsand about eighty images received in a time range from a time point of 30seconds to a time point of 34 seconds.

A method by which the controller 102 of the second terminal 150 selectsthe sample image and a method by which the controller 102 of the secondterminal 150 selects the target image may be changed according toembodiments. FIG. 7 is a flowchart of operation S110 of attempting todetect the face to operation S131 of selecting the target image,according to an embodiment.

Referring to FIG. 7 , in operation S210, one or more sample imagescorresponding to a recent specific time may be selected among theplurality of images included in the stream. The controller 102 of thesecond terminal 150 may select one or more sample images among theimages received for the recent specific time in the stream.

For example, the controller 102 of the second terminal 150 may selecttwo sample images among images received for the last one second. FIG. 8is a reference diagram for describing a process of selecting a sampleimage, according to an embodiment. Referring to FIG. 8 , a first image301 in the stream may have been already selected as a sample image inthe past. The controller 102 of the second terminal 150 may additionallyselect a second image 302 and a third image 303, as the sample image,among images received after a first time point t1 which is a time pointbefore a specific time from a current time.

Referring to FIG. 7 again, in operation S211, the face detection may beattempted in the selected one or more sample images. The controller 102of the second terminal 150 may detect whether a portion corresponding toa face exists with respect to each selected sample image. For example,the controller 102 of the second terminal 150 may attempt to detect aface in the second image 302 and the third image 303.

In operation S220, it may be determined that the face has not beendetected in the selected one or more sample images. The controller 102of the second terminal 150 may determine that the portion correspondingto the face does not exist in the selected sample images.

When the portion corresponding to the face does not exist in the entireselected sample images, the controller 102 of the second terminal 150may determine that the face has not been detected. According to anotherembodiment, when the portion corresponding to the face does not exist inat least one of the selected sample images, the controller 102 of thesecond terminal 150 may determine that the face has not been detected.For example, the controller 102 of the second terminal 150 may determinethat the face has not been detected in the second image 302 and thethird image 303.

In operation S231, the entire images corresponding to the recentspecific time among the plurality of images included in the stream maybe selected as the target images. For example, the controller 102 of thesecond terminal 150 may select the entire images received for the lastone second as the target images. For example, when twenty images persecond are continuously received through the stream, the controller 102of the second terminal 150 may select the about twenty images receivedfor the last one second as the target images. Referring to FIG. 8 , thecontroller 102 of the second terminal 150 may select, as the targetimages, the entire images (including the second image 302 and the thirdimage 303) received after a time point t1 which is a time point before aspecific time from a current time.

FIG. 9 is a flowchart of operation S110 of attempting to detect the faceto operation S131 of selecting the target image, according to anotherembodiment. Referring to FIG. 9 , in operation S310, a new sample imagemay be selected among images newly received in the stream at eachspecific period. The controller 102 of the second terminal 150 mayselect one or more new sample images among the entire images receivedlater than the most recently selected sample image at each specificperiod.

For example, the controller 102 of the second terminal 150 may selecttwo new sample images per second. Referring to FIG. 8 , the controller102 of the second terminal 150 may select, as the new sample images, thesecond image 302 and the third image 303 among the entire imagesreceived later than the first image 301.

Referring to FIG. 9 again, in operation S311, the face detection may beattempted in the new sample image whenever the new sample image isselected. The controller 102 of the second terminal 150 may attempt todetect the face in the newly selected sample image at each specificperiod.

In operation S320, it may be determined that the face has not beendetected in the entire sample images selected within the recent specifictime among the sample images. For example, the controller 102 of thesecond terminal 150 may determine that the face has not been detected intwo sample images selected within the last one second. In other words,the controller 102 of the second terminal 150 may determine that theface has not been detected in the second image 302 and the third image303.

In operation S331, the entire images corresponding to the recentspecific time among the plurality of images included in the stream maybe selected as the target images. For example, the controller 102 of thesecond terminal 150 may select the entire images received for the lastone second as the target images. For example, when twenty images persecond are continuously received through the stream, the controller 102of the second terminal 150 may select the about twenty images receivedfor the last one second as the target images. Referring to FIG. 8 , thecontroller 102 of the second terminal 150 may select, as the targetimages, the entire images (including the second image 302 and the thirdimage 303) received after a time point t1 which is a time point before aspecific time from a current time.

FIG. 10 is a flowchart of operation S110 of attempting to detect theface to operation S431 of selecting the target image, according toanother embodiment. Referring to FIG. 10 , in operation S410, the facedetection may be attempted in a first sample image selected among theplurality of images included in the stream. The controller 102 of thesecond terminal 150 may select the first sample image among theplurality of images. The controller 102 of the second terminal 150 maydetect whether a portion corresponding to a face exists in the firstsample image.

FIG. 11 is a reference diagram for describing a process of selecting asample image, according to another embodiment. Referring to FIG. 11 , afourth image 311 in the stream may have been already selected as asample image in the past. The controller 102 of the second terminal 150may select a fifth image 312 as the first sample image among the imagesreceived later than the fourth image 311.

In operation S411, the face defection may be attempted in each of one ormore second sample images selected among the entire images receivedlater than the first sample image in the stream. The controller 102 ofthe second terminal 150 may select one or more second sample imagesamong the images received later than the first sample image. Thecontroller 102 of the second terminal 150 may detect whether a portioncorresponding to a face exists in each of the second sample images.

For example, referring to FIG. 11 , the controller 102 of the secondterminal 150 may select a sixth image 313 as the second sample imageamong the images received later than the fifth image 312. The controller102 of the second terminal 150 may detect whether a portioncorresponding to a face exists in the sixth image 313.

As another example, the controller 102 of the second terminal 150 mayselect two images as the second sample images. The two images mayinclude the sixth image 313, and another image received later than thefifth image 312 and received earlier than the sixth image 313. Thecontroller 102 of the second terminal 150 may detect whether a portioncorresponding to a face exists in each of the two images.

Referring to FIG. 10 again, in operation S420, it may be determined thatthe face has not been detected in the first sample image and all the oneor more second sample images. The controller 102 of the second terminal150 may determine that the face has not been detected in the firstsample image and the second sample image. For example, the controller102 of the second terminal 150 may determine that the face has not beendetected in the fifth image 312 and the sixth image 313.

In operation S431, the images corresponding to the first sample imageand the second sample image among the plurality of images included inthe stream may be selected as the target images. The controller 102 ofthe second terminal 150 may select the images corresponding to the firstsample image and the second sample image as the target images.

For example, the images corresponding to the first sample image and thesecond sample image may include the first sample image and the entireimages received later than the first sample image among the plurality ofimages. Referring to FIG. 11 , the controller 102 of the second terminal150 may select, as the target images, the fifth image 312 and the entireimages received later than the fifth image 312.

According to another embodiment, the selected target images may includethe first sample image, the one or more second sample images, andneighboring images. The neighboring images may be the entire imagesreceived later than the first sample image and received earlier than thelast received image among the one or more second sample images.Referring to FIG. 11 , the controller 102 of the second terminal 150 mayselect, as the target images, the fifth image 312, the sixth image 313,and the entire images received later than the fifth image 312 andreceived earlier than the sixth image 313.

FIG. 12 is a flowchart of operation S110 of attempting to detect theface to operation S131 of selecting the target image, according toanother embodiment. Referring to FIG. 12 , in operation S510, two ormore sample images may be selected among the plurality of imagesincluded in the stream, wherein the two or more sample images include afirst sample image corresponding to a first time point and a secondsample image corresponding to a second time point having a timedifference from the first time point by a specific time or more.

The controller 102 of the second terminal 150 may select the firstsample image among the plurality of images included in the stream. Thetime at which the first sample image has been received may be the firsttime point. The controller 102 of the second terminal 150 may select, asthe second sample image, an image received after elapse of more than aspecific time from the time at which the first sample image has beenreceived. In other words, the time difference between the time at whichthe first sample image has been received and the time at which thesecond sample image has been received may be more than the specifictime. The specific time may be, for example, one second.

Also, the controller 102 of the second terminal 150 may additionallyselect a sample image among the images received earlier than the firstsample image. Also, the controller 102 of the second terminal 150 mayadditionally select a sample image among the images received later thanthe first sample image and received earlier than the second sampleimage. Also, the controller 102 of the second terminal 150 mayadditionally select a sample image among the images received later thanthe second sample image.

For example, referring to FIG. 11 , the controller 102 of the secondterminal 150 may select, as the first sample image, an image received atan arbitrary second time point t2 in the stream. The controller 102 ofthe second terminal 150 may select, as the second sample image, an imagereceived at a third time point t3 among the images received after elapseof more than one second from the second time point t2.

The controller 102 of the second terminal 150 may additionally select afourth image 311 as the sample image among the images received earlierthan the second time point t2. The controller 102 of the second terminal150 may additionally select a fifth image 312 and a sixth image 313 asthe sample images among the images received later than the second timepoint t2 and received earlier than the third time point t3. Thecontroller 102 of the second terminal 150 may additionally select aseventh image 314 as the sample image among the images received laterthan the third time point t3.

Referring to FIG. 12 again, in operation S511, the face detection may beattempted in each of the selected two or more sample images. Thecontroller 102 of the second terminal 150 may attempt to detect the facein the first sample image, the second sample image, and all theadditionally selected sample images

In operation S520, it may be determined that the face has not beendetected in the first sample image, the second sample image, and theentire sample images corresponding to the time from the first time pointto the second time point among the selected two or more sample images.The controller 102 of the second terminal 150 may determine that theface has not been detected in the first sample image received at thesecond time point t2. Also, the controller 102 of the second terminal150 may determine that a portion corresponding to a face has not beendetected in the second sample image received at the third time point t3.Also, the controller 102 of the second terminal 150 may determine thatthe face has not been detected in the fifth image 312 and the sixthimage 313 selected as the sample images among the images received laterthan the second time point t2 and received earlier than the third timepoint t3. In other words, the controller 102 of the second terminal 150may determine that the face has not been detected in the sample imagesreceived from the second time point t2 to the third time point t3 amongthe selected entire sample images.

In operation S531, the entire images corresponding to the time from thefirst time point to the second time point among the plurality of imagesincluded in the stream may be selected as the target images. Forexample, the controller 102 of the second terminal 150 may select, asthe target images, the entire images received for the time from thesecond time point t2 to the third time point t3. The selected targetimages may include the first sample image, the second sample image, andthe sample images received later than the second time point t2 andreceived earlier than the third time point t3. Also, the selected targetimages may include all the remaining images, which are not selected asthe sample images, among the entire images received later than thesecond time point t2 and received earlier than the third time point t3in the stream.

Referring to FIG. 6 again, after operation S131 of selecting the targetimages, operation S132 of selecting al target region of at least aportion of each of the target images. FIG. 13 is a reference diagramillustrating a selected target region according to an embodiment. Asillustrated in FIG. 13 , the controller 102 of the second terminal 150may select the entire region of each of the target images as the targetregion.

According to another embodiment, the controller 102 of the secondterminal 150 may select, as the target region, a region corresponding toa skin color in each of the target images. The controller 102 of thesecond terminal 150 may detect the region corresponding to the skincolor in each of the target images. The skin color may indicate at leastone color. Since each person has a different skin color, the controller102 of the second terminal 150 may detect regions corresponding tovarious skin colors.

FIG. 14 is a reference diagram illustrating a selected target regionaccording to another embodiment. As illustrated in FIG. 14 , thecontroller 102 of the second terminal 150 may select a region having askin color in a target image as the target region. In other words, eachpixel included in the selected target region may have a skin color.

The controller 102 of the second terminal 150 may select one or moreclosed curves in each of the target images as the target region. Forexample, unlike in FIG. 14 , the region having the skin color mayinclude a plurality of closed curves adjacent to or spaced apart fromeach other The controller 102 of the second terminal 150 may select theentire closed curves as the target region. According to anotherembodiment, the controller 102 of the second terminal 150 may select, asthe target region, one or more closed curves having the largest areaamong the plurality of closed curves.

FIG. 15 is a reference diagram illustrating a selected target regionaccording to another embodiment. As illustrated in FIG. 15 , thecontroller 102 of the second terminal 150 may select, as the targetimage, a rectangular region including a region having a skin color inthe target image. According to another embodiment, the controller 102 ofthe second terminal 150 may select, as the target image, a circular,oval, or polygonal region including the region having the skin color,instead of the rectangular region.

The controller 102 of the second terminal 150 may select one or morepolygonal regions in each target image as the target region. Forexample, unlike in FIG. 15 , the region having the skin color mayinclude a plurality of closed curves adjacent to or spaced apart fromeach other The controller 102 of the second terminal 150 may select onepolygonal region including the entire closed curves as the targetregion. According to another embodiment, the controller 102 of thesecond terminal 150 may select a plurality of polygonal regions as thetarget region. Each of the polygonal regions may include at least one ofthe plurality of closed curves. According to another embodiment, thecontroller 102 of the second terminal 150 may select, as the targetregion, one or more polygonal regions including one or more closedcurves having the largest area among the plurality of closed curves.

Referring to FIG. 6 again, in operation S133, the image processing maybe performed on the selected target region of each of the target images.FIG. 16 illustrates an image, on which the image processing has beenperformed, according to an embodiment. As illustrated in FIG. 16 , thecontroller 102 of the second terminal 150 may delete the selected targetregion in the target image, like in FIG. 15 .

FIG. 17 illustrates an image, on which the image processing has beenperformed, according to another embodiment. As another example, asillustrated in FIG. 17 , the controller 102 of the second terminal 150may apply a blur effect to the target region. FIG. 18 illustrates animage, on which the image processing has been performed, according toanother embodiment. As another example, as illustrated in FIG. 18 , thecontroller 102 of the second terminal 150 may apply a mosaic effect tothe target region. FIG. 19 illustrates an image, on which the imageprocessing has been performed, according to another embodiment. Asanother example, as illustrated in FIG. 19 , the controller 102 of thesecond terminal 150 may substitute the target region with another image.

As another example, the controller 102 of the second terminal 150 mayadjust a color, a brightness, a contrast, or a saturation of the targetregion. Also, the controller 102 of the second terminal 150 may combinethe image processings listed above. For example, the controller 102 ofthe second terminal 150 may apply the blur effect on the target region,reduce the saturation, and reduce the contrast.

Referring to FIG. 3 again, in operation S140, the plurality of imagesincluded in the stream may be displayed. The output interface 105 of thesecond terminal 150 may display the plurality of images. For example,the display included in the output interface 105 of the second terminal150 may continuously display twenty images per second. The plurality ofimages may include one or more images on which the image processing hasbeen performed by the controller 102 of the second terminal 150.

Therefore, the user of the second terminal 150, who makes a video callwith the user of the first terminal 100, can be prevented from beingexposed to obscene images from the counterpart. Also, the user of thesecond terminal 150 can be prevented from sexual shame or discomfortthat he or she may feel from the image from the counterpart. Also, aproper video call between the user of the first terminal 100 and theuser of the second terminal 150 may be guided.

In operation S150, a request for cancelling the image processing may bereceived. For example, the user of the second terminal 150 may want toview the original of the received image, while taking the exposure toinappropriate images lying down. The display included in the outputinterface 105 of the second terminal 150 may output a message askingwhether to cancel the image processing. For example, the outputinterface 105 of the second terminal 150 may output a message “No faceis detected. Please press the button to view the original.” The user ofthe second terminal 150 may press the button included in the inputinterface 101 of the second terminal 150 as a response to the message.In other words, the input interface 101 of the second terminal 150 mayreceive the request for cancelling the image processing from the user ofthe second terminal 150.

In operation S160, the image received after the reception of the requestamong the plurality of images included in the stream may be displayedwithout image processing. The controller 102 of the second terminal 150may determine that the face has not been detected in the image receivedafter the reception of the request. In spite of the above determination,the controller 102 of the second terminal 150 may not perform imageprocessing on the image received after the reception of the request. Thecontroller 102 of the second terminal 150 may display one or more imagesreceived after the reception of the request without image processing.

FIG. 20 is a flowchart of an image display method according to anotherembodiment. Referring to FIG. 20 , in operation S600, a video callsession with the first terminal 100 may be established. Thecommunication interface 104 of the second terminal 150 may establish thevideo call session with the first terminal 100.

In operation S610, a stream including a plurality of images captured bythe first terminal 100 may be received through the video call session.The communication interface 104 of the second terminal 150 may receivethe stream from the first terminal 100 through the video call session.The stream may include a plurality of images.

In operation S620, the plurality of images included in the stream may bedisplayed. The output interface 105 of the second terminal 150 maydisplay the plurality of received images.

In operation S630, face detection is attempted in each of one or moresample images selected among the plurality of images included in thestream. The controller 102 of the second terminal 150 may select atleast one of the plurality of images. The controller 102 of the secondterminal 150 may detect whether a portion corresponding to a face existsin each selected sample image.

In operation S640, it may be determined that the face has not beendetected in at least some of the sample images. The controller 102 ofthe second terminal 150 may determine that the face has not beendetected in one or more sample images. When the face has not be detectedin the sample image, inappropriate images may be included in theplurality of images.

In operation S650, the video call session may be terminated. Thecommunication interface 104 of the second terminal 150 may terminate thevideo call session with the first terminal 100. Therefore, the user ofthe second terminal 150, who makes a video call with the user of thefirst terminal 100, can be prevented from being exposed to inappropriateimages from the counterpart.

FIG. 21 is a flowchart of an image display method according to anotherembodiment. Hereinafter, descriptions of parts that were previouslydescribed will be omitted.

The first terminal 100 and the second terminal 150 may establish a videocall session and transmit and receive a stream including a plurality ofimages captured by each terminal. Hereinafter, referring to FIG. 21 , amethod of displaying an image performed by a terminal receiving a streamfrom a counterpart terminal will be described. For convenience ofexplanation, the description will be made on the assumption that thesecond terminal 150 receives a stream including an image in which noface is detected from the first terminal 100. However, the presentdisclosure is not limited to this embodiment, and the first terminal 100may receive a stream including an image in which no face is detectedfrom the second terminal 150. Furthermore, although the flowchart ofFIG. 21 is described herein with reference to a particular order, invarious embodiments, states or operations herein may be performed in adifferent order, or omitted, and additional states may be added.

In operation S2110, the second terminal 150 may receive a streamincluding a plurality of images captured by the first terminal 100 fromthe first terminal 100.

In operation S2120, the second terminal 150 may determine whether thereis an image (or a first image) in which no face is detected among theplurality of images included in the stream.

According to an embodiment, the second terminal 150 may determinewhether there is the image in which no face is detected, based onmetadata information included in the stream. The stream received fromthe first terminal 100 may include metadata information together withthe plurality of images captured by the first terminal 100. The metadatainformation includes information about images, and may include, forexample, information about the image in which no face is detected, timestamp information corresponding to the image in which no face isdetected, etc. Accordingly, the second terminal 150 may extract themetadata information from the stream received from the first terminal100 and determine whether there is the image in which the face is notdetected in the received stream through the metadata information. Themetadata information may be included in a header file of the streamincluding the plurality of images.

According to another embodiment, the second terminal 150 may determinewhether there is the image in which the face is not detected among theplurality of images using a learned face detection model. The facedetection model is a type of data recognition model that detects whethera human face is included in an image and may be a learning model basedon an artificial neural network.

In operation S2130, when it is determined that there is the image inwhich no face is detected, the second terminal 150 may perform imageprocessing on the image in which no face is detected among the pluralityof received images. The second terminal 150 may perform image processingto reduce visibility of the image in which no face is detected among theplurality of received images. The second terminal 150 may perform imageprocessing in which a picture of the image in which no face is detectedis blocked and a voice is maintained. Accordingly, a user of the secondterminal 150 cannot see the picture of the image in which no face isdetected, and can only hear the voice.

According to an embodiment, based on the time stamp information obtainedfrom the metadata information, the second terminal 150 may select theimage in which no face is detected from among the plurality of imagesincluded in the stream as a target image and perform the imageprocessing on the target image. For example, the second terminal 150 mayselect all images corresponding to the time stamp information among theplurality of images included in the stream as the target image. Thesecond terminal 150 may also select all images after a first imagecorresponding to the time stamp information among the plurality ofimages included in the stream as the target image. The second terminal150 may further select all images corresponding to a time period from afirst time point to a second time point of the time stamp informationamong the plurality of images included in the stream as the targetimage. However, the above selected target images are merely examples,and the target image is not limited thereto. The second terminal 150 mayperform image processing on the entire region of the selected targetimage. For example, the second terminal 150 may delete the entire regionof the target image, may apply a blur effect or a mosaic effect to theentire region of the target image, may adjust a color, a brightness, acontrast, or a saturation of the entire region of the target image, ormay substitute the entire region of the target image with another image.

According to another embodiment, the second terminal 150 may select theimage in which no face is detected as a target image based on adetermination result using the learned face detection and perform imageprocessing on the target image. For example, when a value of thedetermination result for each of the plurality of images included in thestream using the learned face detection model does not satisfy apredetermined condition, the second terminal 150 may select the image inwhich the value of the determination result does not satisfy thepredetermined condition as the target image.

In operation S2140, the second terminal 150 may display a plurality ofimages by replacing the image in which no face is detected with an image(or a second image) on which the image processing has been performed.The second terminal 150 may display, in a first region on a screen ofthe second terminal 150 having a video call session established with thefirst terminal 100, the plurality of images including the image on whichthe image processing has been performed. The screen of the secondterminal 150 may include the first region displaying an image of a userof the first terminal 100 and a second region displaying an image of auser of the second terminal 150.

FIG. 22 is a diagram for explaining a state in which the second terminal150 displays a received image when the first terminal 100 transmits astream including an image in which no face is detected to the secondterminal 150.

FIG. 22 shows an example of the display state illustrated assuming that,after a video call session between the first terminal 100 and the secondterminal 150 is established, during transmission and reception ofstreams including images captured by each terminal, the user of thefirst terminal 100 transmits, to the second terminal 150, an image inwhich no face is detected, for example, an image in which the bodyexcluding the face of the user of the first terminal 100 is exposed.Each of the first terminal 100 and the second terminal 150 may include acommunication interface, a user interface, a memory storinginstructions, and at least one processor.

When a video call session between the first terminal 100 and the secondterminal 150 is established, the first terminal 100 may transmit a firststream including a first image captured by the first terminal 100 to thesecond terminal 150 and receive a second stream including a second imagecaptured by the second terminal 150 from the second terminal 150. Thesecond terminal 150 may transmit the second stream to the first terminal100 and receive the first stream from the first terminal 100.

The processor (not shown) of the second terminal 150 may execute theinstructions stored in the memory (not shown) to receive, through thecommunication interface unit (not shown), a stream including a pluralityof images captured by the first terminal 100 from the first terminal100.

The processor of the second terminal 150 may determine whether there isthe image in which no face is detected among a plurality of imagesincluded in the stream.

According to an embodiment, the processor of the second terminal 150 maydetermine whether there is the image in which no face is detected amongthe plurality of images in the received stream, based on metadatainformation included in the stream. To this end, the first terminal 100may check whether a face is detected in each image before transmittingthe image captured by the first terminal 100 to the second terminal 150.The first terminal 100 may execute a face detection algorithm todetermine whether a face is detected in each image captured by the firstterminal 100 and, if a face is not detected, may include informationabout an image in which a face is not detected or time stamp informationof the corresponding image, etc. in the stream in the form of metadatainformation to transmit it to the second terminal 150. The secondterminal 150 may extract the metadata information from the streamreceived from the first terminal 100 and determine whether there is theimage in which the face is not detected in the received stream throughthe metadata information.

According to another embodiment, the processor of the second terminal150 may determine whether there is the image in which no face isdetected among the plurality of images in the received stream using thelearned face detection model.

When it is determined that there is the image in which no face isdetected, the processor of the second terminal 150 may perform imageprocessing on the image in which no face is detected among the pluralityof images.

According to an embodiment, based on the time stamp information obtainedfrom the metadata information, the processor of the second terminal 150may select the image in which no face is detected from among theplurality of images included in the stream as a target image and performthe image processing on the target image. For example, when there areimages in which no face is detected at each specific time point, theprocessor of the second terminal 150 may select all images correspondingto the time stamp information from among the plurality of imagesincluded in the stream as the target image. As another example, whenimages in which no face is detected continuously appear after a certaintime point, the processor of the second terminal 150 may select allimages after a first image corresponding to the time stamp informationfrom among the plurality of images included in the stream as the targetimage. As another example, when an image in which no face is detectedfor a specific time period is displayed, the processor of the secondterminal 150 may select all images corresponding to a time period from afirst time point to a second time point of the time stamp informationfrom among the plurality of images included in the stream as the targetimage.

According to another embodiment, the processor of the second terminal150 may select the image in which no face is detected as the targetimage based on a determination result using the learned face detectionmodel and perform image processing on the target image. For example,when a value of the determination result for each of the plurality ofimages included in the stream using the learned face detection modeldoes not satisfy a predetermined condition, the processor of the secondterminal 150 may select the image in which the value of thedetermination result does not satisfy the predetermined condition as thetarget image and perform image processing on the target image.

The processor of the second terminal 150 may perform image processing onthe entire region of the target image. The processor of the secondterminal 150 may perform image processing to reduce visibility of theimage in which no face is detected. The processor of the second terminal150 may perform image processing in which a picture of the image inwhich no face is detected is blocked and a voice is maintained.

The processor of the second terminal 150 may display a plurality ofimages through the user interface unit (not shown) by replacing theimage in which no face is detected with an image on which the imageprocessing has been performed. The screen of the user interface of thesecond terminal 150 may include a first region displaying an image of auser of the first terminal 100 and a second region displaying an imageof a user of the second terminal 150. The processor of the secondterminal 150 may display, in the first region, a plurality of imagesreceived from the first terminal 100 and including an image on whichimage processing has been performed, and may display, in the secondregion, an image captured by the second terminal 150.

Referring to FIG. 22 , it can be seen that the second terminal 150displays, in the first region, an image including a face of a user ofthe first terminal 100 and displays, in the second region, an imageincluding a face of a user of the second terminal 150. After that, itcan be seen that the second terminal 150 performs image processing onthe entire region of an image in which the face of the user of the firstterminal 100 is not detected so that the user of the second terminal 150cannot see the image in which the face of the user of the first terminal100, and then displays, in the first region, the image on which theimage processing has been performed. In this case, it can be seen thatthe second terminal 150 continuously displays the image of the user ofthe second terminal 150 in the second region and the first terminal 100may display the image in which no face is detected without separateimage processing on the first terminal 100.

According to the embodiments set forth above, it is possible to preventthe user who makes the video call with the counterpart from beingexposed to obscene images from the counterpart. Also, it is possible toprevent the user who makes the video call with the counterpart fromsexual shame or discomfort that he or she may feel from the image fromthe counterpart. Also, it is possible to guide a proper video callbetween the users.

Embodiments may be embodied in a non-transitory computer-readablerecording medium having recorded thereon computer-executable instructioncodes, such as a program module executable by the computer. Thenon-transitory computer-readable recording medium may be any availablemedium which can be accessed by the computer and may include anyvolatile and non-volatile media and any removable and non-removablemedia.

Furthermore, the non-transitory computer-readable recording medium mayinclude any computer storage medium and communication medium. Thecomputer storage medium may include any volatile and non-volatile mediaor any removable and non-removable media embodied by a certain method ortechnology for storing information such as computer-readable instructioncodes, a data structure, a program module, or other data. Thecommunication medium may include computer-readable instruction code, adata structure, a program module, other data of modulated data signals,or other transmission mechanisms, and may include any informationtransmission medium.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. An image display method comprising: receiving,from a first terminal, a stream including a plurality of images capturedby the first terminal; determining, at a second terminal, whether thereceived stream includes a first image in which no face is detectedamong the plurality of images; wherein determining is based on metadatainformation included in the stream; in response to determining that thereceived stream includes the first image, selecting, as target images,all images corresponding to a time period from a time pointcorresponding to the first image to a second time point; whereinselecting target images is based on time stamp information obtained fromthe metadata information; performing, at the second terminal, imageprocessing on the target images to generate a second image; anddisplaying, at the second terminal, the plurality of images by replacingthe target images with the second image.
 2. The image display method ofclaim 1, wherein the image processing is performed to reduce visibilityof the target images.
 3. The image display method of claim 1, whereinthe image processing comprises blocking a picture of the target imagesand maintaining a voice relating to the target images.
 4. The imagedisplay method of claim 1, wherein the displaying comprises displaying,in a first region on a screen of the second terminal having a video callsession established with the first terminal, the plurality of imagesincluding the second image, and wherein the screen of the secondterminal comprises the first region further displaying an image of auser of the first terminal and a second region displaying an image of auser of the second terminal.
 5. The image display method of claim 1,wherein the selecting comprises selecting all images corresponding tothe time stamp information from among the plurality of images includedin the stream as the target images.
 6. The image display method of claim1, wherein the selecting comprises selecting all images after the firstimage as the target images.
 7. The image display method of claim 1,wherein the image processing for target images is performed on an entireregion of the target images.
 8. The image display method of claim 1,wherein: the determining is performed using a learned face detectionmodel, and selecting the target images is based on a determinationresult using the learned face detection model.
 9. An image displaydevice comprising: a communication interface; a user interface; a memorystoring instructions; and a processor configured to communicate datawith the communication interface, the user interface and the memory, theprocessor further configured to execute the instructions to: receive,from a first terminal through the communication interface, a streamincluding a plurality of images captured by the first terminal;determine whether the received stream includes a first image in which noface is detected among the plurality of images; wherein determining isbased on metadata information included in the stream; in response todetermining that the received stream includes the first image,selecting, as target images, all images corresponding to a time periodfrom a time point corresponding to the first image to a second timepoint; wherein selecting target images is based on time stampinformation obtained from the metadata information; perform imageprocessing on the target images to generate a second image; and display,through the user interface, the plurality of images by replacing thetarget images with the second image.
 10. The image display device ofclaim 9, wherein the processor is configured to execute the instructionsto perform image processing to reduce visibility of the target images.11. The image display device of claim 9, wherein the processor isconfigured to execute the instructions to perform image processing toblock a picture of the target images and maintain a voice relating tothe target images.
 12. The image display device of claim 9, wherein: theuser interface includes a first region configured to display an image ofa user of the first terminal and a second region configured to displayan image of a user of the image display device, and the processor isconfigured to execute the instructions to display, in the first region,the plurality of images including the second image.
 13. The imagedisplay device of claim 9, wherein the processor is configured toexecute the instructions to select all images corresponding to the timestamp information from among the plurality of images included in thestream as the target images.
 14. The image display device of claim 9,wherein the processor is configured to execute the instructions toselect all images after the first image as the target images.
 15. Theimage display device of claim 9, wherein the processor is configured toexecute the instructions to perform image processing on entire regionsof the target images.
 16. The image display device of claim 9, whereinthe processor is configured to execute the instructions to: determinewhether the received stream includes the first image using a learnedface detection model; select the target images based on a determinationresult using the learned face detection model; and perform the imageprocessing on the target images.
 17. A non-transitory computer-readablerecording medium having recorded thereon a program to execute an imagedisplay method, the method comprising: receiving, from a first terminal,a stream including a plurality of images captured by the first terminal;determining, at a second terminal, whether the received stream includesa first image in which no face is detected among the plurality ofimages; wherein determining is based on metadata information included inthe stream; in response to determining that the received stream includesthe first image, selecting, as target images, all images correspondingto a time period from a time point corresponding to the first image to asecond time point; wherein selecting target images is based on timestamp information obtained from the metadata information; performing, atthe second terminal, image processing on the target images to generate asecond image; and displaying, at the second terminal, the plurality ofimages by replacing the target images with the second image.